With a GLOBAL modifier, the statement
displays the global status values. A global status variable
may represent status for some aspect of the server itself
(for example, Aborted_connects), or the
aggregated status over all connections to MySQL (for
example, Bytes_received and
Bytes_sent). If a variable has no global
value, the session value is displayed.

With a SESSION modifier, the statement
displays the status variable values for the current
connection. If a variable has no session value, the global
value is displayed. LOCAL is a synonym
for SESSION.